CVE-2021-3156

Exploitation

Exploited in the wild. Listed in the CISA Known Exploited Vulnerabilities catalog on 2022-04-06. Federal remediation due 2022-04-27.

SSVC decision

• ExploitationactiveCISA reports credible evidence of active exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

99.96% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 99.9% of scored records. A rank, not a probability.

NVD base score

7.8 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2021-01-26 00:00Z5 YR AGO

Last updated

2025-10-21 23:35Z1 YR AGO

Reserved

2021-01-15

Assigning CNA

mitre

Record state

PUBLISHED

Severity

High (CVSS 7.8)

CNA CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weaknesses

• CWE-193Off-by-one ErrorBase
• CWE-122Heap-based Buffer OverflowVariant

Data version

5.1

Document digest

e60a9d31942b816ae37b34acfb7db6b3297f620d3425d35ada952cbc44f0f048

• lists.debian.org[debian-lts-announce] 20210126 [SECURITY] [DLA 2534-1] sudo security updatehttps://lists.debian.org/debian-lts-announce/2021/01/msg00022.htmlmailing-list
• seclists.org20210126 Baron Samedit: Heap-based buffer overflow in Sudo (CVE-2021-3156)http://seclists.org/fulldisclosure/2021/Jan/79mailing-list
• www.openwall.com[oss-security] 20210126 Baron Samedit: Heap-based buffer overflow in Sudo (CVE-2021-3156)http://www.openwall.com/lists/oss-security/2021/01/26/3mailing-list
• security.gentoo.orgGLSA-202101-33https://security.gentoo.org/glsa/202101-33vendor-advisory
• www.debian.orgDSA-4839https://www.debian.org/security/2021/dsa-4839vendor-advisory
• lists.fedoraproject.orgFEDORA-2021-2cb63d912ahttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LHXK6ICO5AYLGFK2TAX5MZKUXTUKWOJY/vendor-advisory
• lists.fedoraproject.orgFEDORA-2021-8840cbdccdhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CALA5FTXIQBRRYUA2ZQNJXB6OQMAXEII/vendor-advisory
• www.openwall.com[oss-security] 20210127 Re: Baron Samedit: Heap-based buffer overflow in Sudo (CVE-2021-3156)http://www.openwall.com/lists/oss-security/2021/01/27/1mailing-list
• www.openwall.com[oss-security] 20210127 Re: Baron Samedit: Heap-based buffer overflow in Sudo (CVE-2021-3156)http://www.openwall.com/lists/oss-security/2021/01/27/2mailing-list
• tools.cisco.com20210129 Sudo Privilege Escalation Vulnerability Affecting Cisco Products: January 2021https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sudo-privesc-jan2021-qnYQfcMvendor-advisory
• www.kb.cert.orgVU#794544https://www.kb.cert.org/vuls/id/794544third-party-advisory
• seclists.org20210211 APPLE-SA-2021-02-09-1 macOS Big Sur 11.2.1, macOS Catalina 10.15.7 Supplemental Update, and macOS Mojave 10.14.6 Security Update 2021-002http://seclists.org/fulldisclosure/2021/Feb/42mailing-list
• www.openwall.com[oss-security] 20210215 Re: sudo: Ineffective NO_ROOT_MAILER and Baron Samedithttp://www.openwall.com/lists/oss-security/2021/02/15/1mailing-list
• www.oracle.comhttps://www.oracle.com//security-alerts/cpujul2021.html
• www.sudo.wshttps://www.sudo.ws/stable.html#1.9.5p2
• www.openwall.comhttps://www.openwall.com/lists/oss-security/2021/01/26/3
• packetstormsecurity.comhttp://packetstormsecurity.com/files/161160/Sudo-Heap-Based-Buffer-Overflow.html
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20210128-0002/
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20210128-0001/
• packetstormsecurity.comhttp://packetstormsecurity.com/files/161230/Sudo-Buffer-Overflow-Privilege-Escalation.html
• packetstormsecurity.comhttp://packetstormsecurity.com/files/161270/Sudo-1.9.5p1-Buffer-Overflow-Privilege-Escalation.html
• packetstormsecurity.comhttp://packetstormsecurity.com/files/161293/Sudo-1.8.31p2-1.9.5p1-Buffer-Overflow.html
• support.apple.comhttps://support.apple.com/kb/HT212177
• kc.mcafee.comhttps://kc.mcafee.com/corporate/index?page=content&id=SB10348
• www.beyondtrust.comhttps://www.beyondtrust.com/blog/entry/security-advisory-privilege-management-for-unix-linux-pmul-basic-and-privilege-management-for-mac-pmm-affected-by-sudo-vulnerability
• www.synology.comhttps://www.synology.com/security/advisory/Synology_SA_21_02
• www.openwall.com[oss-security] 20210914 Re: Oracle Solaris membership in the distros listhttp://www.openwall.com/lists/oss-security/2021/09/14/2mailing-list
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuoct2021.html
• www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.html
• www.openwall.com[oss-security] 20240130 Re: CVE-2023-6246: Heap-based buffer overflow in the glibc's syslog()http://www.openwall.com/lists/oss-security/2024/01/30/8mailing-list
• www.openwall.com[oss-security] 20240130 CVE-2023-6246: Heap-based buffer overflow in the glibc's syslog()http://www.openwall.com/lists/oss-security/2024/01/30/6mailing-list
• packetstormsecurity.comhttp://packetstormsecurity.com/files/176932/glibc-syslog-Heap-Based-Buffer-Overflow.html
• seclists.org20240204 CVE-2023-6246: Heap-based buffer overflow in the glibc's syslog()http://seclists.org/fulldisclosure/2024/Feb/3mailing-list
• www.vicarius.iohttps://www.vicarius.io/vsociety/posts/sudoedit-pwned-cve-2021-3156
• www.cisa.govhttps://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-3156government-resource